Field of the Invention
This invention relates in general to feeding devices, and in particular to a new and useful device for straightening and feeding articles such as letters.
At mail distributing centers, letters of differing format are vertically transported between two conveyor belts of a so-called cover belt section. The pulling of the letters causes individual letters to twist upwards. In order to correct this effect, the letters pass through a free wheeling section.
In certain places in the mail distribution machines, the letters must be turned through 180.degree. about their lengthwise axis. Whereas previously their lower lengthwise edges had been aligned, this is no longer the case after the letters are turned in a turning section, due to the different width of the letters. If they must afterwards be straightened once again, and especially if they enter an additional cover belt section at an angle from the free wheeling section with a bottom conveyor for collection and straightening of the letters, they will be shifted between the two side belts during the straightening and generally must alter their direction of transport in the vertical plane.
A single stage free wheeling section is necessary after a pulling mechanism, and a two-staged free wheeling section after a turning section. In these free wheeling sections, the letters are displaced between the side belts by the straightening. To enable such displacement without damage to thick letters, the distance between the side belts in the area of displacement of the letters is chosen such that thick letters can be adequately shifted. But thin letters slip down through the side belts and are prevented from falling out by guide plates mounted at the side between the bottom belt and the side belts. This known method with simple guide plates, however, has the serious disadvantage that improperly glued flaps of the letters can be ripped open or even torn off during the displacement of the letters between the conveyor belts.